Fix the check for flood of arp. Add UT for same.

Change-Id: Id2a003c815436cdb7df80820f0a6c8ad6ac6eeba
Closes-bug: 1402627

src/vnsw/agent/oper/inet_unicast_route.cc

@@ -420,13 +420,14 @@ bool InetUnicastRouteEntry::FloodArp() const {
     Agent *agent =
         (static_cast<InetUnicastAgentRouteTable *> (get_table()))->agent();
     const AgentPath *local_path = FindPath(agent->local_peer());
-    if (local_path && (local_path->is_subnet_discard() == false))
-        return false;
-
-    if (GetActiveNextHop()->GetType() == NextHop::RESOLVE)
-        return false;
+    //Only look for subnet route programmed via IPAM(i.e. will have local path
+    //as subnet discard) and active path of that subnet route should not be
+    //resolve.
+    if (local_path && (local_path->is_subnet_discard() == true) &&
+        (GetActiveNextHop()->GetType() != NextHop::RESOLVE))
+        return true;
 
-    return true;
+    return false;
 }
 
 // Handle add/update of a path in route. 

src/vnsw/agent/test/test_route.cc

@@ -451,6 +451,7 @@ TEST_F(RouteTest, LocalVmRoute_1) {
     EXPECT_TRUE(rt->dest_vn_name() == "vn1");
     EXPECT_TRUE(rt->GetActivePath()->vxlan_id() == VxLanTable::kInvalidvxlan_id);
     EXPECT_TRUE(rt->GetActivePath()->tunnel_bmap() == TunnelType::MplsType());
+    EXPECT_FALSE(rt->FloodArp());
     DeleteVmportEnv(input, 1, true);
     client->WaitForIdle();
 
@@ -469,6 +470,7 @@ TEST_F(RouteTest, RemoteVmRoute_1) {
     EXPECT_TRUE(rt->dest_vn_name() == vrf_name_);
     EXPECT_TRUE(rt->GetActiveLabel() == MplsTable::kStartLabel);
     EXPECT_TRUE(rt->GetActiveNextHop()->GetType() == NextHop::TUNNEL);
+    EXPECT_FALSE(rt->FloodArp());
 
     DeleteRoute(NULL, vrf_name_, remote_vm_ip_, 32);
     EXPECT_FALSE(RouteFind(vrf_name_, remote_vm_ip_, 32));